I may possibly buy a car from a friend in Surat Thani.  I live in Jomtien.  I would fly there and drive the car back.

In terms of future use, am I better-off doing the transfer of ownership at a DLT in Surat Thani or drive it to Jomtien and complete the transfer in Chonburi?   

I recall reading posts on TV/AN about owners having issues when their cars are registered in a province other than their official (TM30) residence.

You will meet your friend in person to do the business?

Do it at Surat Thani.

It's easier if both parties can go to the DLT for the transfer.

You will need your passport AND a proof of residence. 

Otherwise paperwork (power of attorney) to be filled/signed/authorized for doing the procedure in Chonburi.

 

There is no need to change plates. Where the car is registered makes no difference in annual tax / insurance/ inspection procedures.

You can pay tax at every DLT.